The invention relates to a fastener, especially for pipe clamps, with two parts, which are to be connected to one another, and with a movable fastening part, one part essentially having a strip with at least one stop and the second part having a plate with an opening having a width which corresponds at least to the width of the strip and of the stop and the fastening part being movable against a spring force out of the width of the strip and of the stop.
Fasteners of the type under discussion here are used particularly for fastening objects to ceilings, walls, floors and the like. Frequently, access to the fastening locations is extremely difficult for the installing personnel. Furthermore, the overhead installation requires the use of considerable force. For these reasons, it should be possible to install such fasteners very easily. Especially for fastening pipes with the help of pipe clamps, it should be possible for the operator to close the pipe clamp with only one hand, since the pipes, which are to be installed, generally are bulky objects, which in some cases are also difficult to fasten.
A fastener of the type mentioned is known, for example, from the EP 0597805 B1 in conjunction with pipe clamps and has two parts, which are to be connected together. The one part has a strip with stops and the other part a plate with an opening for the strip with the stops. A locking element, connected by a joint to the plate, covers part of the opening and is mounted so that it can be swiveled away from the opening against the force of a spring. The axis of rotation of the locking element extends parallel to the surface of the plate. In order to produce the spring force, a spring element is provided, which is supported at the locking element and at the plate. The locking element covers the opening to such an extent, that the part, which remains free, corresponds to the axial projection of the strip without stops.
If this strip is passed through the opening, covered by the locking element, the latter swivels away about the axis of rotation. After reaching the end position of the strip, which is passed through the opening, the locking element swivels back, at the same time gripping behind the corresponding stops. In order to loosen the fastener, the stop must be moved back so far, that it lies outside of the circle area of the locking element, which can be swiveled about the axis of rotation. This is very disadvantageous when the pipe clamp is being dismantled from the pipe, since the force, which must be applied by the installing personnel, is very large. Under some circumstances, the known fastener cannot be opened any more at all, since the stop no longer can be moved back the necessary distance. Furthermore, it is expensive to manufacture the known fastener since the latter consists of several parts. This has a negative effect economically.
It is an object of the present invention to create a fastener, which can be opened and closed in a simpler and user-friendly manner and, in addition, can be produced economically.
Pursuant to the invention, this objective is accomplished owing to the fact that the locking part is constructed as a spring clip and has at least one spring leg, which rests on the surface of the plate, opposite the inlet side of the pipe clamp, and is located partially in the width region of the strip and of the stop and can be moved out of the width region of the strip and of the stop by a rotational movement about an axis of rotation, formed approximately parallel to the insertion direction.
Owing to the fact that the movable spring leg rotates parallel to the surface of the stop, the strip does not have to be moved counter to the insertion direction when the fastener is opened. If need be, this measure can be taken up in order to reduce the friction between the spring leg and the surface of the stop. In addition, it is easier and, with that, more economical to manufacture the fastener, especially the locking part, since it is constructed in one piece by a spring clip. The one-part construction also has a positive effect on a reliable and user-friendly handling.
Advisably, two stops are provided opposite to one another on the strip and the spring clip is constructed essentially U-shaped, the two ends of the spring clip being formed by legs of the spring, which are disposed parallel to one another and rest on the surface of the plate, opposite the inlet side. As a result of the thereby possible symmetrical construction of the fastener, there is an optimum distribution of load and, consequently, the load carrying capacity of the fastener is high. Because the load is distributed over two legs of the spring, the locking part can also be constructed from a material of lesser thickness, as a consequence of which the locking part is installed more easily and the configuration is more user friendly.
Advisably, the legs of the spring extend outwardly from a free end of the plate, in order to make a clearly visible and easily accessible operating means for loosening the fastener available to the installing personnel.
A leg stop is disposed preferably in the swiveling region of the spring leg, between the opening and the free end of the plate. Accordingly, the fastener can be opened by pressing together the two legs of the spring, extending beyond the free end of the plate, especially when the spring clip is constructed essentially U-shaped. Owing to the fact that the spring legs rotate about the leg stop, they move apart in the region of the opening.and, thus, release the strip with its stops.
The leg stop advantageously is constructed as an impression in the surface of the plate, opposite the inlet, for producing the leg stop economically.
Owing to the fact that advisably the free ends of the spring legs are constructed U-shaped and partially embrace the free end of the plate, the surface, clamped by the U shape parts being perpendicular to the surface of the plate opposite the inlet, the spring clamp is held by friction at the free end of the plate. Due to the configuration described, the installation during the fabrication of the fastener is very simple.
Advantageously, the spring clip is formed from a material with a modulus of elasticity of more than 100 kN/mm2. Accordingly, the spring clip has a high elasticity, which has a positive effect on the reliability and the service life of the fastener.
Preferably, the spring clip is made from a spring steel. This material makes available properties, which are suitable for such stresses and can be processed economically.
In accordance with a further proposal of the invention, the strip has at least two stops, which are disposed behind one another, and the distance between two stops, which are located behind one another, preferably corresponds to one to five times the maximum diameter of the spring leg. As a result, the fastener can be finely adjusted.